What is difference between A36 steel and Q235D steel?

A36 steel is a standard structural carbon steel grade commonly used in the United States, known for its good weldability and machinability, with a minimum yield strength of 36,000 psi. Q235D steel, on the other hand, is a Chinese steel grade that also has good weldability and is typically used in structural applications, but it has a lower yield strength of around 235 MPa (approximately 34,000 psi) and better toughness at lower temperatures. The primary differences lie in their mechanical properties, standards, and regional usage.